Answer:
They erected scientific equipment, made precise observations of conditions on the lunar surface, and collected samples of the Moon's soil and rocks.
Explanation:
i hope it is right im really sorry if its not
Because 25% is half of 0.5 and the half life of 
is given as 5,715, the time it takes to reach this amount should just be double the half life: 11430 years.
However, in other cases the problem may not have easy numbers, so below is a more mathematical approach.
The half life formula is 
.
Solving for t gives:
Given information:
Plug in given values and solve for t.
With correct significant figures, this would be 11000 years.
Answer:
they are eamples of chemical properties
Explanation:
flammibility is the chemical makeup of the element that makes it flamable and reactivitie is the chemical makeup of an element that is able to reacte to another element
Heat of vaporization (During which the temperature stays the same)
